Here is a schematic of the circuit I built. The circuit consist of a primary coil, secondary coil, iron core, 2 lithium ion cells connected together, forming a battery, and a multimeter to measure current. I think the battery sometimes gets hot. Should i put a resistor between the battery and primary coil?

 

(Releates to a kind of spark coil)

Yes or use a longer and smaller piece of wire to raise the resistance of the primary.

You can also reduce the voltage.

It might be good idea to place a normally open button in series so you can charge a quick tap of the button.

 

So why should I use a resistor?

 

Hello,

The origenal Ruhmkorff coil uses an interupter:
https://en.wikipedia.org/wiki/File:Ruhmkorff_coil_schematic_1.svg
https://en.wikipedia.org/wiki/Induction_coil

Bertus

 

Your circuit does not show an interrupter contact set on the primary. You will not get any output from the secondary with a steady DC current through the primary.

Les.

 

Your circuit does not show an interrupter contact set on the primary. You will not get any output from the secondary with a steady DC current through the primary.

Les.

...which is why I suggested a push-button (for now).

 

Actually I did build an interrupter. The interrupter consist of a paper clip, glued to an aluminum strip, the aluminum strip is connected to 1 terminal of a battery, When I connect the battery, current flows through a primary, generating a magnetic field, which pulls the paper clip upwards, the aluminum strip is on a second aluminum, so primary current flows through, first 1st aluminum strip, then through 2nd aluminum strip, then through the primary coil, the second aluminum strip is connected to the primary coil, and 1 end of the primary is connected to 1 terminal of the battery. The 1st aluminum strip is connected to the negative terminal of the battery and the primary coil is connected to the positive terminal of the battery. So when the magnetic field pulls the paperclip up, it moves the 1st aluminum strip up, interrupting current flow through the primary.

I am not sure how to draw an interrupter in a schematic. I will look it up on the internet.

I already read that wikipedia on ruhmkorff coil on the internet.

I have already tested the interrupter a lot, the magnetic field does pull the paperclip upwards against the force of gravity.

(Releates to a kind of spark coil)

Yes or use a longer and smaller piece of wire to raise the resistance of the primary.

You can also reduce the voltage.

It might be good idea to place a normally open button in series so you can charge a quick tap of the button.

You still have not told me why use a resistor?

 

It is a simple solution but lowering your power supply voltage strikes me as more efficient.

 

Why is lowering power supply more efficient?

 

Hello,

The origenal Ruhmkorff coil uses an interupter:
https://en.wikipedia.org/wiki/File:Ruhmkorff_coil_schematic_1.svg
https://en.wikipedia.org/wiki/Induction_coil

Bertus

That's the real name for a Model T Ford ignition coil. Also known as a"trembler coil". https://en.wikipedia.org/wiki/Trembler_coil Used the coil core as an electromagnet to make the points move.

 

Should i put a resistor between the battery and primary coil?

Or you could add more turns of wire on both primary and secondary. It has to be done on both to keep the ratio of windings correct.

 

Dont forget it must be resonant with leak inductance and leak capacitance. Thus the geometry of a coil makes ultimate difference on the power consumption.